My friends pup are 4 weeks old,absolutely beautiful and raised to the highest of standards but every one of them has watery eyes,no discharge,eyes arent red or sore simply just watery.she has asked her vet about it and he said this can happen when the puppies teeth start to come in and it should clear up as they grow but of course new puppy owners are noticing and questioning why the faces are wet.She has used the same food for previous litters and raised in the same room so no changes at all.Is there anything she can do to clear this up and any idea why this is happening?Mum doesnt have watery eyes.

I had this in my one and only toy litter I ever bred.  I was told by many it was the food which I tried changing. Like your friend I have my pups in a spotless environment and there was nothing I did that made a difference.
Unfortunately both pups continued with this problem and one of them who was cream coloured became very stained no matter how much I cleaned it. I kept her and gave a family member the other pup. It turned out they had very narrow tear ducts and I had mine operated to try and stretch this which I was told can help and it made no difference.
She is now coming up 2 and I keep her face clipped but it is still gets wet. I will obviously never breed her and despite importing her mum and her being fine I will not risk breeding from her again either.
I hope in your friends case the vet is right.